NWCG Glossary of Wildland Fire (PMS 205)

Map showing the different classes of visible area covered by a lookout point or points; may differentiate between seen areas, indirectly visible areas, and blind areas, or only between seen areas and blind areas. Also known as seen area map.

Basic weather conditions prescribed for flight under Visual Flight Rules: ceiling above 1,000 feet (300 m) and flight visibility in excess of 3 miles (5 km).

An NDVI-derived image of vegetation greenness compared to a very green reference such as a golf course.

Maximum distance at which a given object can just be seen by an observer with normal vision.

The inventory and planning actions taken to identify visual values and to establish objectives for managing those values; and the management actions taken to achieve the visual management objectives.

The visible physical features on a landscape (e.g., land, water, vegetation, animals, structures and other features).

A systematic and thorough scan of the wildland fire environment for an object or feature as it relates to seeing or sight.  This scan may be aided by magnification when necessary.

Readily changeable into vapor at low temperatures.

Readily vaporized organic materials which, when mixed with oxygen, are easily ignited.

An event dealing with response to volcanic activity.

An appointment/agreement that meets the following conditions:

The person does not receive compensation (other than reasonable reimbursement or allowance for expenses actually incurred)

A fire department company or a response unit, the members of which are not paid.

A fire department of which some or all members are unpaid.

Legally enrolled firefighter under the fire department organization laws who devotes time and energy to community fire service without compensation other than Worker's Compensation or other similar death and injury benefits.

Miniature whirlwinds trailing from the wingtips of any aircraft in flight. Vortex will be in the form of a horizontal whirlwind with velocities up to 25 mph (40 km) per hour or more. Also created by action of rotor blades on helicopters; these whirlwinds tend to move downward toward the ground. If an aircraft flies low over a fire, vortices may reach the ground and suddenly cause violent and erratic fire behavior.

The walk test is designed to determine the ability to carry out light duties. It consists of a one-mile test with no load that approximates an aerobic fitness score of 35. A time of 16 minutes, the passing score for this test, ensures the ability to meet emergency and evacuate to a safety zone. 

The leading edge of a relatively warm air mass which moves in such a way that warm air replaces colder air that moves away from a region. Winds associated with warm frontal activity are usually light and mixing is limited. The atmosphere is relatively stable when compared to cold front activity.

The amount of deviation from a straight line when the hose is hydrostatically tested; usually expressed in inches.

The official delegation of authority to contracting officers and procurement officers establishing the dollar amount and type limits for acquisitions.

A shallow channel or raised barrier, e.g., a ridge of packed earth or a thin pole laid diagonally across the surface of a road or trail so as to lead off water, particularly storm water. (Frequently installed in firelines on steep slopes to prevent erosion.) 

Apparatus utilizing an air compressor and positive displacement pump coupled to the same engine, plumbed to a non-pressurized tank, for producing foam. The operation involves injecting compressed air into a liquid stream containing a suitable foaming agent.

Apparatus utilizing a pressurized tank, hose, and nozzle for producing foam by injection of compressed air or gas into a liquid stream downstream from the pumping source. The liquid stream must contain a suitable foaming agent.

The pH content of a hose jacket determined after boiling in distilled water in a laboratory test.

A force created by the rapid acceleration or deceleration of water, commonly created by opening or closing a valve too quickly. Pressures developed in a water hammer, proportional to the mass multiplied by the square of the velocity, can damage a pipe or hose. 

Any strategically located supply of water that is readily available for pumps, tanks, trucks, helicopters, or fire camp use.

The type of water source.

A map showing location of supplies of water readily available for pumps, tanks, trucks, camp use, etc.

Any ground vehicle capable of transporting specified quantities of water.

A type of bleeder valve designed for installation at convenient points in hose lines to permit drawing off water for filling backpack pumps or other use without interfering with pump or nozzle operation.

Any body of water including lakes, rivers, streams and ponds whether or not they contain aquatic life.

A disturbance that transfers energy from one point to another point and may take the form of a deformation of pressure or temperature. In the atmosphere such disturbances may result in major storms or merely result in changes in cloud, wind and temperature conditions. Development of a wave on a front usually slows the advance of the front due to transfer of energy to the wave development and movement. 

In aviation forecasting, an expression of hazardous weather conditions not predicted in the zone weather forecast, as they affect the operation of air traffic.

A field collected in the ICS 209 containing a brief summary of how the current weather is affecting the incident and how the anticipated weather will affect the incident.

Part of the National Fire Danger Rating System (NFDRS).  Number used to determine seasonal risk class for a protection unit, calculated by multiplying peak monthly average by two and adding seasonal monthly average.

Master and metadata standards exist and data complies with the standard.

The contractor furnishes all equipment operating supplies.

A low expansion foam type with few and varied bubbles and rapid drain time which is used for rapid penetration and fire extinguishment.

A line of water, or water and chemical retardant, sprayed along the ground, and which serves as a temporary control line from which to ignite or stop a low-intensity fire.

Fire retardants mixed with water and stored in tanks at air attack bases for immediate use by airtankers.

Water with added chemicals, called wetting agents, that increase water's spreading and penetrating properties due to a reduction in surface tension.

The difference between the wet and dry-bulb temperatures recorded by a psychrometer; used in conjunction with the dry-bulb temperature as a measure of the relative humidity of the air.

The lowest temperature to which air can be cooled by evaporating water into it at a constant pressure when the heat required for evaporation is supplied by the cooling of the air. It is measured by the wet bulb thermometer, which usually employs wetted wicking on the bulb as a cooling (through evaporation) device.

In a psychrometer, the thermometer with its bulb covered with a jacket of clean muslin which is saturated with distilled water before an observation.

A chemical that when added to water reduces the surface tension of the solution and causes it to spread and penetrate exposed objects more effectively than the untreated water.

A widespread rain that over an extended period of time significantly reduces fire danger. One-tenth of an inch may be sufficient to reduce fire danger in grass fuel models. One half inch may be necessary for timber fuels under closed canopies.